Automatic road crowner



Patented Get. 27, 1925.

UNITED Sv'lATEti JOHN BRISBEN WALKER, MOUNT FALCON, 001303151110.

AUTOMATIG ROAD GROWHER. 7

Application filed December 24,1920 Serial n. 432,932.

To all whom it may concern;

Be it known that 1, JOHN Biiisnnn WALKER, a citizen of the United States of America, and a resident of Mount Falcon, in the county of Jefferson and State of Colorado, have invented certain new anduseful Improvements in Automatic Road Crowners, of which the following is a specification.

The object of this invention is to provide an apparatus, which by its mathematically calculated construction, will, without the op eration of leversor other guidance, when at tached to a tractor, or truck, draw the plowed and narrowed land into a symmetrical crown perfect of curvature, leaving no depressions, and shedding the water throughout all ordinary storms, leaving the crown smooth, hard and compact.

A further object is to provide an apparatus which will recrown with mathematical exactness, a highway built under the Brisben \Valker specifications, at a merely nominal cost of from fifty cents to one dollar per mile, should there be ruts formed from any cause as for instance heavy trucking during continued wet snows.

A further object is to provide an apparatus which by its simple and inexpensive operation permits the construction of highways of a high economic efficiency.

In the accompanying sheet of drawings which forms a part of this application,

Figure l is a plan view of an automatic road-crowner constructed in accordance with this invention.

Figure 2 is an elevation of one of the blades.

Figure 3 is a detail to a larger scale showing the manner of connecting the blades together and to the drawbars.

The automatic road-crowner consists of a front steel blade 10 and a rear steel blade 11 so framed that when dragged behind a trac tor or truck moving along the centre of ahighwaythey will produce a perfect road crown, whose curvature corresponds with that of the steel crowner. The blades may be conveniently from fourteen to twentytwo or more feet in length according to the width of road to which it is desired to especially adapt the apparatus. A typical length of eighteen feet is herein selected for illustration of the invention. The blades are one-half inch in thickness by six inches in width and are vertically arched or curved so as to have a six inch rise at the centre for an eighteen foot length. They are also benthorizontally concave toward the frontsothat'the middle will be about eighteen inches back ofthe ends. Heavybolts l2 3.2;ahout five feet in length andone inch in diameter .arespaced about four feet apart parallel and connect the front and rear blades. I These passthrough holes .two inches below the top edges of bothvhl'ades so as to permit of planks and sand bags being supported thereon. The rear ends of these bolts 13, 13 pass through these endsand the rear blade holding them rigidly at the desired angle. The front ends of the heavy bolts pass loosely through the holes in the front blade and are kept from pulling out thenuts 14, 14 and by reason of the looseness together with a limited flexibilit of bothbolts and draw bars allow both 0 the blades to conform more uniformlyto irregularitiesin the general level ofthe road. A central drawbar 15 and diagonal drawbars 16,16 of one-half inch by twoinch steel are bent at right angles at their-rear ends and lie over the top edge of the front blade and are rigidly attached thereto near the middle and ateachend by bolts 17, 17 and at their front ends are attached by boltslS, 18 to a clevis 19. These drawbars are conveniently about 19 or more feet inlength accordingto the width of the blades and the relative lengths of the central and side drawbars are such that the frontblade is held by them at the desired concave. The rear blade-is held at the same concave by connecting bolt-s while the apparatus is being dragged on the road. The clevis besides having a central hole is provided with holes about nine inches to either side to either of which the draft chain of a tractormay be attached whenever it is necessary to draw more earth from the other side toward the centre to properly centre the crown of the road. Planks 20, 20 are laid on the heavy bolts to form a platform which is, weighted down with one or more bags of sand as needed.

bolts are bent at right angles and small Typical specifications for the construction ofa new highway, in which an'automatic road-crowner according tov this inven- 7 rowed to secure a higher centre and leave wider ditches on either side with the final furrows. The road is next harrowed until clods are thoroughly broken up. With a hand rake all stones and pebbles are carefully dislodged and removed from the road. The ditches are cleaned out to a width of three feet with scrapers and shovels and the material thrown into depressions remaining after the plowin and harrowing so as to bring the road nearly as possible to a uniform crown with a width. of eighteen feet. The road crowner is now used, being drawn by a tractor traveling along the middle of the roadway, and it is drawn back and forth over the stretch of road at this stage of construction until the surface assumes a uniform curvature.

-When the crowner is first drawn over the roughly prepared surface there may be por tions which have too much crown and other portions where the crown is too little, or there may be a twist in the surface so that one blade may have to drop or rise at one end more than the corresponding end of the other blade. At either of such places there will be an automatic partial adjustment to the actual road crown by reason of the fact that the two blades are not rigidly framed together but are connected by bolts which are more or less yielding and the a further fact that the blades are not secured to rigid framework and have some flexibility. At such places the standard crown is reached after the crowner has been drawn over the road a number of times. 7 The entire road is next rolled, beginning at the edges, with a heavy motor-roller. The road is gone over with the roadcrowner. Next, clean coarse screened sand, free from all stones and pebbles is spread uniformly over the road to a depth of onehalf inch. After heavy rains and the use of the road by trucks the automatic roadcrowner is again dragged over the road, closing up all ruts and restoring an even crown which will rapidly shed water to both ditches. ,his should be done as early as possible after the storm. A motor truck or tractor should be able to cover from twenty to thirty miles per day at a cost of about 5510. This large radius of action is important, covering large stretches of road before drying or hardening sets in.

With such treatment, systematically followed, highways can be maintained that in a second coating of sand, one-quarter to onehalf inch, but'not more, may be applied. An essential feature of this system is the binder formed by a small coating of sand with clay, thus creating a species of cement hard surface. The use of larger amounts of sand is injurious rather than beneficial.

Since the connecting bolts between the blades in this automatic road-crowner loosely pass through the holes in the front blade and are parallel, the rear blade can.

be removec from the front blade thus rendering the apparatus more compact for car- 'e or storage.

l. A yieldingly framed road-crowner comprising vertically arched and horizontally concave front and rear transverse blades each extending continuously from one side of the road to the other, the blades being yieldingly held in edge relation to the road and horizontally concave whereby they automatically adjust their curvature and alignment partially to the road while being drawn thereover. L

2. A yieldingly framed road-crowner comprising vertically arched and horizontally concave front and rear transverse blades each extending continuously from one side of the road to the other, drawbars to the ends of which the front blade is connected, and connecting bolts between the blades the ends of which are connected to the rear blade and loosely connected to the front blade whereby they automatically adust their curvature and alignment partially to the road while being drawn thereover.

A yieldingly framed road-crowner comprising vertically arched and horizontally concave front and rear transverse blades each extending continuously from one side of the road to the other, drawbars to the ends of which the front blade is connected, and connecting bolts between the blades the ends of which are connected to the rear blade and loosely pass through holes in the front blade by which the blades are held in parallel relation.

4. A yieldingly framed road crowner comprising vertically arched and horimentally concave front and rear transverse blades each extending continuously from one side of the road t0 the other, drawbars to the ends of which the front blade is connected, and connecting bolts between the blades the ends of which are connected to the rear blade and loosely pass through holes in the front blade by which the bolts are held in parallel relation and the blades are held in edge relation to the road and horizontally concave while being drawn thereover. 7

JOHN BRISBEN WALKER. 

